In several cultures, during medieval and modern times, fasting has been used for homosexuality. Fasting is defined as “a willing abstinence or reduction from some or all food, drink, or both, for a period of time”, so it is similar to keeping a diet. Fasting has also been used since antiquity as a healing tool for many diseases.

According to historian Caroline Bynum, “Many patristic [early Christian, from c. AD 100 to either AD 451 or to the 8-th century] writers associated food with lust and urged abstinence as a method of curbing sexual desire. John Cassian, writing for monks in the early fifth century, said: ‘It is impossible to extinguish the fires of concupiscence (strong sexual desire) without restraining the desires of the stomach.”

Lust without voracity would certainly be considered a monstrous phenomenon; since these two are so united and concrete, that, had there been any possibility of disjoining them, the pudenda would not have been affixed to the belly itself rather than elsewhere… First, the belly; and then immediately the materials of all other species of lasciviousness are laid subordinately to daintiness: through love of eating, love of impurity finds passage.

The Penitential of Cummean (c. 650), an Irish penitential, which was much circulated in Europe during the eighth and ninth centuries, described different penances (punishments) for sexual misconduct, including homosexuality. The Penitential calls the penances “medicine for the salvation of the soul”. It begins with a chapter on gluttony, followed by a chapter on fornication. For those who committed sodomy it ordered a penance of 7 years. It does not detail the penance, but in the previous paragraphs it describes the penance for fornication by a priest who has taken the vow of a monk:

He shall ask pardon every hour and shall perform a special fast every week except in the fifty days from Easter to Pentecost. After the special fast he shall have bread without limit and a tidbit smeared with some butter (that is to say a quarter measure) and he shall live like this on Sundays, while on other days he shall have a portion of dry bread (made from a twelve-potentae vessel of flour) and a meal enriched with a little fat, garden vegetables, a few eggs, British cheese, a Roman half-pint (equal to twelve hen’s eggs) of milk on account of the frailty of the body in this age, a Roman pint of whey or buttermilk (equal to twelve hen’s eggs) for his thirst and some water if he does physical hard work. His bed shall be made of only a little straw. During the three forty-day periods he shall increase his penance as far as his strength allows.

The penitential of Columban which dates to around the year 600, says, “But if one commits fornication as the Sodomites did, he shall do penance for ten years, the first three on bread and water; but in the other seven years he shall abstain from wine and meat, and [he shall] not be housed with another person forever.”

John The Faster, Patriarch of Constantinople (582-595 A.D.) in his canon XVIII excludes the sodomist from communion for three years, with the additional penance of fasting and toward evening xerophagy. Xerophagy is a kind of Christian fast in which only bread, salt, water, vegetables may be eaten and meat, fish, milk, cheese, butter, oil, wine, and all seasonings or spices are excluded.

Fasting has also been used in other non-Christian cultures. The Laws of Manu, the most popular Hindu law book of medieval and ancient India, prescribed food restriction for homosexual acts: “If a man has shed his semen in non-human females, in a man, in a menstruating woman, in something other than a vagina, or in water, he should carry out the ‘painful heating’ vow.” The Painful Heating vow is described as follows, “If one lives one day on cow’s urine, one day on cow-dung, one day on milk, one day on sour milk, one day on clarified butter, one day on a decoction of Kuśa grass, and during one day and night, on air.”

An early medical text where diet is mentioned as a remedy for homosexuality is a medieval medical treatise on passive homosexuality, Treatise on the hidden Illness, attributed to Abū Bakr Muhammad ibn Zakariyyā al-Rāzī (854 CE – 925 CE), a Persian polymath. Among other treatments for homosexuality he mentions fasting and a special diet:

The treatments mentioned by me are right for young and the affluent people. In connection with others, your aim in treating them should be to make them loose weight and diminish the blood. Thus they should be ordered to fast, to give up drinking wine, to use vinegar for seasoning…..They should also stick to foods such as qaris, masus, hulam, hisrimiyah, with gourds and lentils, drink constantly oxymel…

In China, sodomy was first punished in 1790 by the Qing Code. Sodomy with consent was penalized with one month in the cangue and 100 heavy blows. A cangue was a device used for corporal punishment and the person wearing the cangue could not eat, unless he was helped by others.

Fasting seems to continue to be used in several countries, like in Ecuador, China, and Great Britain. Today, https://orthodoxwiki.org (a free-content encyclopedia for Orthodox Christianity) mentions fasting as one of the “spiritual weapons” that should be used for homosexuality. The foods that are not eaten during a fast in Orthodox Christianity include: meat, dairy products, eggs, olive oil (especially where olive oil is not a major part of the diet, the rule is sometimes taken to include all vegetable oils, as well as oil products such as margarine), wine and other alcoholic drink.

Everyone eats, but few know how to eat. Only a person who eats in such a way as to achieve a normal human balance lives a happy life. Misfortune strikes those whose body and minds are not healthy. Such people often evidence sexual deviation as one among their many symptoms. In point of fact, homosexuality is quite common in the West, perhaps a thousand times more so than in the East…You can cure sexual deviation with macrobiotics.

The healthy man is yang, active and strong, while the healthy woman is yin and should be passive in sexual life. If man is too yin, which arises from eating too much yin food (e.g., sugar and fruit) “he will be very unhappy”; if a women is too yang from digesting too much yang food (animal products), unhappiness will result… Women are singled out for a special warning: if you happen to “detest a man’s sexual desire,” then you must have eaten too much yang food, which if not remedied will lead a woman to “become homosexual or love animals to an extreme degree.”